RESUMO
BACKGROUND: In gastric cancer (GC), extracapsular growth (ECG) pattern of lymph node metastases is associated with decreased overall survival rates compared to intracapsular lymph node metastases (ICG). Epithelial-to-mesenchymal transition (EMT) plays a pivotal role in hematogenous metastatic spread. Aim of the present study was to analyze if EMT related genes are involved in the growth pattern of lymph node metastases in GC. METHODS: Out of our prospective database with 529 patients who underwent surgical resection for GC between 2002 and 2014 forty lymph node positive patients were identified (20 ECG, 20 ICG). The expression of 84 EMT-associated genes were analyzed by RT2 Profiler PCR Array (n = 20). Results were validated by Real-Time PCR (n = 20). RESULTS: GC with ECG showed differently expressed EMT related genes. GC leading to ECG showed an upregulation of three and downregulation of eleven genes. Those differences, however, could not be confirmed in PCR analysis. CONCLUSIONS: This study demonstrates that EMT related genes are not responsible for the different growth patterns of lymph node metastases in GC. Further studies are required to evaluate the underlying mechanisms of ECG in GC as it might provide a potential therapeutic target for this subgroup of more aggressive tumors in the future.
Assuntos
Transição Epitelial-Mesenquimal/genética , Extensão Extranodal/genética , Metástase Linfática/genética , Neoplasias Gástricas/genética , Neoplasias Gástricas/patologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos RetrospectivosRESUMO
PURPOSE: Gastric cancer is the third leading cause of cancer-related death. Recently, innovative diagnostic and prognostic molecular subtypes have been proposed. We revealed that extranodal extension (ENE) of lymph-node metastases independently influences survival. Therefore, the aim of the present study was to evaluate novel molecular subtyping with regard to the growth pattern of lymph-node metastases. METHODS: A total of 189 gastric carcinomas with lymph-node metastases were analyzed. The expression of p53, SOX2, SOX9, and the mismatch-repair gene products MLH1, PMS2, MSH2, and MSH6 were analyzed by immunohistochemistry. To determine the correlation with EBV infection, in situ hybridization for EBV-encoded small RNA (EBER) was applied. RESULTS: ENE was present in 36% of patients. EBV-positive carcinoma was evident in 5.8%, and p53 aberrant (chromosomal instable) tumors in 22.2%, a gastric cancer with deficient mismatch-repair status in 9%, and MSS/p53neg/EBVneg tumors were seen in 63% of patients. There was no significant correlation between the presence or absence of ENE and the molecular subtypes. However, a significant association between molecular subgroups and the Lauren classification, the oncogene SOX2, and tumor grading was detected. CONCLUSION: The present findings suggest that alterations in gastric cancer leading to ENE are not associated with alterations underpinning the molecular subgroups. Nonetheless, molecular subtyping on the basis of IHC and ISH is feasible and might become clinical routine. Thus, further studies are needed to clarify the mechanisms of extranodal extension in gastric cancer.
Assuntos
Adenocarcinoma/classificação , Adenocarcinoma/secundário , Biomarcadores Tumorais/genética , Biomarcadores Tumorais/metabolismo , Neoplasias Gástricas/classificação , Neoplasias Gástricas/patologia , Adenocarcinoma/genética , Adenocarcinoma/metabolismo , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Seguimentos , Humanos , Metástase Linfática , Masculino , Pessoa de Meia-Idade , Prognóstico , Neoplasias Gástricas/genética , Neoplasias Gástricas/metabolismo , Taxa de Sobrevida , Adulto JovemRESUMO
BACKGROUND: Extra-capsular growth (ECG) describes the extension of neoplastic cells beyond the lymph node capsule. Aim of this study was to investigate the prognostic value of ECG and its association with a stem cell like phenotype indicated by expression of the transcription factor SOX9 in gastric cancer. METHODS: By histological evaluation, 199 patients with nodal positive gastric cancer or adeoncarcinoma of the esophageal-gastric junction (AEG) were divided into two groups according to the presence (ECG) or absence (ICG) of extracapsular growth in at least one nodal metastasis. Of these, 194 patients were stained for SOX9 and SOX2 using immunohistochemistry. Seventeen nodal negative patients (pT3/4, pN0, pM0) served as controls. RESULTS: Seventy-three patients (36.7%) showed ECG. ECG was associated with lower overall survival (p < 0.0001), advanced pT- (p = 0.03) and pN- category (p < 0.0001) and lymphovascular invasion (p = 0.014). In multivariate analysis, ECG was found to be an independent prognostic factor (HR = 2.1; 95% CI 1.7-3.4; p = 0.001). SOX9 expression correlated significantly with ECG (96% SOX9 high in ECG patients vs. 79% SOX9 high in patients with ICG; p = 0.002). Controls showed significantly reduced SOX9 expression compared to nodal positive carcinomas (59% vs. 85% high SOX9 expression; p = 0.006). No significant correlation of ECG and SOX2 (59% SOX2 negative in ECG patients vs. 64% in patients with ICG, p = 0.48) could be obtained. CONCLUSIONS: Patients with ECG exhibit poorer prognosis and ECG was found to be an independent prognostic factor. Thus, ECG turns out to be a morphological biomarker for a more aggressive phenotype in gastric cancer. This is supported by the fact that ECG correlates with the expression of SOX9, which has been described in the context of pro-oncogenic properties of tumours. However, the fact that SOX2 failed to show significant results indicate that ECG is not associated with a distinct cancer stem cell phenotype in gastric cancer.
